1. Field of the Invention
The invention relates to a print control apparatus which can communicate with a host computer and an image output apparatus and to a print control method and a memory medium.
2. Related Background Art
FIG. 16 is a block diagram showing an example of a data processing system is to which such a print control apparatus can be applied.
In the case where data of a host computer is printed from an output apparatus such as a color copier or the like of an electrophotographic system, as shown in FIG. 16, the system needs a printer controller 1302 for receiving code data such as a page description language (PDL) or the like which is sent from the host computer 1301, generating page information comprising dot data (bit map data) on the basis of a command shown by the code data, and sequentially transmitting the dot data to a color copier 1303.
The printer controller 1302 is constructed of: a PDL circuit for converting the page description language sent from the host computer 1301 into the dot data; a bit map memory for storing the dot data converted by the PDL circuit; and a data transmitter for transmitting the data in the bit map memory to the color copier 1303.
In the conventional system, it will be noted that the bit map memory in the printer controller 1302 is necessary, for storing the dot data.
In recent years, the realization of high precision in print output from color copiers and the like has been demanded. Although a method of raising the print resolution of the color copier is considered, for example, in a case of changing the resolution from 400 dpi to 600 dpi, this entails that the bit map memory capacity is at least doubled, so that there is a problem in that the cost increases remarkably.
To solve this problem, there is a method whereby compression (compressing process) is performed on pixel data, the compressed data is stored in the bit map memory, and the data is sequentially transmitted to the color copier while performing decompression (decompressing process). Although the capacity of the bit map memory can be reduced by using such a method, if a highly efficient compression is needed, there is a problem of occurrence of deterioration of the picture quality.